Sentinel lymph node identification using near-infrared fluorescence imaging and ultrasound in patients with breast cancer

Abstract

605 Background: Recently, we reported a novel technique of sentinel lymph node (SLN) identification using near-infrared fluorescence imaging that provides high detection and low false-negative rates. Furthermore, we present the combination of near-infrared fluorescence imaging and ultrasound to obtain better outcomes. Methods: This study enrolled 91 patients with a breast tumor less than 3 cm in diameter. Their mean age was 52 years. Preoperative TNM stage was I in 61 cases, IIa in 21, and IIb in 9, respectively. Initially axillary lymph nodes were identified by ultrasound and their locations were marked on the axillary skin. And then the dye of indocyanine green was injected subdermally in the areola. Subcutaneous lymphatic channels draining from the areola to the axilla became visible by fluorescence imagings (Photodynamic eye: PDE, Hamamatsu Photonics Co.) immediately. After incising the axillary skin 1 cm cranial side from the disappeared point of fluorescence image, SLN was then dissected under the guidance of fluorescence with adequate adjustment of sensitivity. Results: Lymphatic channels and SLN were successfully identified by PDE in 89 patients (identification rate: 97.8%). The SLN of remaining two patients were compensated by ultrasound. The number of fluorescence SLN ranged from 0 to 11 (mean: 3.9). An adequate adjustment of sensitivity of PDE provided with less time-consuming to identify SLN. The identification rate of near-infrared fluorescence imaging and ultrasound was 93.4% (85/91). Twenty-two patients (24.2%) had lymph node metastases pathologically. One of them was not recognized by fluorescence imaging due to the whole massive metastasis of LN. There were no intra- or postoperative complications associated with SLN identification. Conclusions: This combination method was considered more effective to detect SLN intraoperatively than near-infrared fluorescence imaging alone. An adequate adjustment of sensitivity of PDE enabled a pin-point identification of SLN. No significant financial relationships to disclose.